SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a8ba817dceb41b127262b73bc161a4bd55d0cf2cd7e4da65e47113819b857bc9' 
  AND token = 'Xq3RriSC2kY5PZcmGNPCeAHDOgXOqh3mrlU2IYb1ppw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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