SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d78580a217e5b809298966b62da145e6bdeba6800d5b464dcb3e55cc8067cf4' 
  AND token = 'ozhy1ih/sr+lzjaJ0ui3cfLgKIyENQWyBMIU7Udrf8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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