SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8837283593dbb66b766b042716d95309d02d1af5b1f360c1e24c17e02a203f51' 
  AND token = 'bVN0yv+US3udzV2Aczl5t1ZPO3ago84VsDikRliVU0E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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