SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f4426d7b4bb0e02ecfc675f2fefa631054dc4806a91be61f141f5adbd30ce859' 
  AND token = '32Mk3PXWIBPW/vIGvLqXRa+KuWoHOBw+GOXBDHXvij4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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