SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b602855254d2844f0cb8574bdfb6ee95668a72a87031aee2e1225a733e8503a' 
  AND token = 'r1x8zru6qyfjuNkLxZdpYk6TEIhm1v3tczJYlYpdL3Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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