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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3c68b354ecc3646a1f377533f77b49a19c2b6da449692d139d8ddd01523ea53' 
  AND token = '3wI0VEe61HxbD0RGJgHLrVce5Push3F6lOgZTAcc+qE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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