SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '731c98524bd56e79c3809eab1bef9faedc73e05b98f278ef347ceadf63b9d611' 
  AND token = 'A9SQuAF72NyzjJ5nnkIYbuY0o2rCofiTQy4PQYjjSaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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