SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e4c67269430afefb73217d5a226234f8d23cf097c14db862bf6a7ff5170ff89b' 
  AND token = 'w7+BJzGfybxpinQQrqZN2SlUQdpIIkKAHi0Xhoa/cZQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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