SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34a29e800e41bd0bafa9f48aff08bb03f77ecc0aa905c95ec664c2d07b552500' 
  AND token = 'tfWyOdkwakoX0SqaCQb46zYNsR+jUt0SCm4ZPWhr8fY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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