SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6570b876da31a64b63e26f15e63f389a2526b1010bc7870ad2bf5baf433b426e' 
  AND token = 'h2BDH3pzpoJxHHfME7mAeR+Kyg4hMY1zq+WiggA/kiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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