SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a678c6f55e73dba82e664cc0a96431ab13d0c4ac86aec5785cf9ec6a9904be33' 
  AND token = 'Hoy5scWT/VOSxv0VuSHzRrH8GcEN2Ma/LE3Uk6xanjE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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