SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b58102656720bd72c3fedd7ca8369d100f1363b7784e494cf076fffadfd0094' 
  AND token = 'lLboR1oT9LRNd9jymlVXMQynxkd9vgsMaR+cmlDeHbY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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