SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd792254fa1a2e8244b3ac6d6a27572202952c0d68cfffe1ba7628e20a3e347eb' 
  AND token = '2fgEsbAD/C2stEuRdIJYEPpxlWuKE1ZPKj91dmq6eM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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