SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1629b38285384b1d3d20295469d586078e31f5e2cfb9a58cbc4df2676c3549bf' 
  AND token = '0J0LH4Ka7JhQduDTJTW3rVwTCQGWFRbU8cjd0Bz/yiY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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