SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '440fbc158320388505dbeb6f8f2af38fbb45c7ab471d65782498c1a725b3bb0f' 
  AND token = 'cllQTJ39ewTjQEfZ42kef3vLs1bFad1ChhMjJNlhrtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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