SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a04d6dc982145a449d85d743c5893bc3f120ac1d092127fecd347979bfa75b5c' 
  AND token = 'hrQEbPze7l4CMkabQDH38eVCMbA/pXNA8qzxI3w3cNs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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