SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f62c4409dda13cccea8cf18ff0efa7ab7fea5a482a94c105db93ffc35cc1dc1c' 
  AND token = 'hqxQyo5cR/4lGyJQ9JyeYo5TpNVR9p9+GfQh8ZfL4HU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}