SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1789531dce44fd71139393ad12ffeaf3c8dec32706b46949858438a92bc3a45e' 
  AND token = 'VzSPpF/Fk+p/TwuJCH+T0s1jJFZWXwZMwaMeuygRGkQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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