SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '8461e6067b6f2df7b23f65fd5ae96ec61d3d92d02f570bab912840306745aa67' 
  AND token = 'gBttnW/W/jT7aFULgUVnA+N36pMd1VvND51LDe9X+Ac=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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