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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3de75de4db7f02d3ce75c472e1d3d10aea2d2a677d526f0ba44cd76dc9f04c4c' 
  AND token = 'wupSr7dxbR4Z4PKuRlBx57aCD1VVj5BMKwg/KmN9Cbs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}