SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '36a4dc4a94d728948a3441a35fe95052185370585cc982f45c45561c77e21962' 
  AND token = '0WtrNwfHUmj/nTuacaB1YO02CEbHMDyUHG5K10AswUg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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