SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5ecb5edbc0c4dbf0f4acd2b7f99a6fcf3a8b21dc39490052c4ba950c4f04a270' 
  AND token = 'AF7XRQkDxGlG+DDZhm/t3v1Cv0g7BtZDzeqJFhUUMbM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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