SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd98385593a1650c0ce2224d027bf24ec99f57fe5633722c52e2f23b967f740d9' 
  AND token = 'MvAD/GiCjimdN8jm/qIv7a00cOym8lmtOhyhF9DAcig=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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