SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fc95ff03d13b1c581725d556f23f8e9262b58aa43beabefb9ede402cb837707' 
  AND token = 'wsy0GFTXb6YX+vMXwAZ90k9xyWNr1JeqMQ7xK25QgGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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