SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1510dfd01f389d7fa36a7932618225b034383dbff122abe6315d341ad7f22393' 
  AND token = 'o7yb8vUr9kuU8PEGTJXFFF9birrpxNaezi9wjW/IGWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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