SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bd8511b257b99b8a21de545efc659576a845f3e93a957492d6895c2c22dcca87' 
  AND token = 'DJFiw9rBH8hy3JaTFxVVO0+BKUWPIumweZbAI0eqgAU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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