SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24c6f58eafbe3af9007ff3063d454ca1481ee3ca850e8b4f9ac97cae0e41edf5' 
  AND token = '743159ByHjhySEJas9/OWZHOTdCakxkVzmRRzeS5Z+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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