SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7883550c4981e7c6dbdf57466da59055b31cf65664c1a03263295e0ad610af7' 
  AND token = 'r+yVufVCt0gcPDKdstqA1ZiS6VwLU0ZDAMawIYZUtbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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