SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e04e82800c75a8b0a62fd4fa1991f89e57f36ef706c807fd8ee66cc6851ac0d8' 
  AND token = '3PwSnBWxtj7+sbqCklNi94JYU2DebyNoudII2K+JZiI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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