SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '271aa70b97dc2f7b2c15bb5912e5d42b197c768bbab24c167f756fb2af441062' 
  AND token = '6pY4fdrunIRbcEyCXzKd77ptCqYhagk8XfnWzU+pCu4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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