SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f266277b67f71c2ae48a9ac0fc554ce686355f909d578694546a07c29ebd7dbe' 
  AND token = 'PGUfDXvebsM9SDkva38hFQRzfoBZHzHOqtyICR4bJZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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