SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '700e058d9a80caa4fd79756487dd834e2d56cd14d793527f583f3d47864f9cdf' 
  AND token = 'm2KVHoGYQpKY8vKbS+zhaPIzBCMPcu1+Wukyy+KFzb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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