SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee2f86a2ff59c646e1647c07facb272a027b7206efabedb21d761778ee2892af' 
  AND token = 'EzxC3+9ekX3Ptp4QMFRBh1f9uC6KfcyQkChqE5XgPwA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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