SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bdb1edc139db50e0fcb01070ef593809054dd25dd155f3d6a40d23e762cdb611' 
  AND token = 'XEvsDQfAMEqgHN+1rrEEbPWaswkthTEg3zmaM9g5FnQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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