SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2722bd2eb8d929ed26f7040d05d398f4cb47142d0a5d0da40a432b86daed5be' 
  AND token = 'Ei24EED0X7ux6D4OEHgNQlB3hRcEv57R9YemEJq/Mas=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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