SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c36a11435b88a29a871006dfd96b072776182658e216219466b04b2a7317c181' 
  AND token = 'DaIGPLw5M/Ugh3O18hLBFdTf0igiBNUl2Bg9UNYipHQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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