SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e854f6c01ffa867559bb7b5213d7f579bbc94ae53f9dcd248f6a3f6ce8c9af75' 
  AND token = 'BT2gM9FOJh2nZsgwc9sJI9lq3LKQ2gFhgd8W3xBf784=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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