SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '1b7a28495017659541f126a9509267084a51a3a3b580d51027175b2c78aae274' 
  AND token = 'rWp78ihtdXecKLhV9d4h03AFi36HKTTfrE9Z1gIdEd4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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