SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad96023677c316402351469aedfe069f6558bf730911e722581916f1ffcede44' 
  AND token = 'biAdoq0kI71f3+rxKvn1rD+KHk9yqmHb4YRt8ZTQAPI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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