SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c93bb326236ea50e437e939dc5fa03c1581fde566605dd7bdd861c99f7406d7f' 
  AND token = 'lo55xi7YAfUuqUPMi7Pe4MMt1N17e45PMpevQcWX16c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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