SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bbbeb9619146c1c6c694294712dfb4692aeab3f7961b07afa518c606658d0206' 
  AND token = 'MXjbjYZEtlJxic04idbgJhdBqYwmQPxKfjZvwOBjmjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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