SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '463f2e59168dcef3bdd50d8620dce48d8fb5737d8b30a95938cddf2e67c042e7' 
  AND token = 'FVHi+oPwGpSS9siCibOnMk1USgsPf1IifDNr44LwBH4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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