SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '735dcda13596046111bc98dc27fb6551afd72c4af1da19081524f2095b0d0a8f' 
  AND token = 'CTWNmha5Zw8d/l6G5sTTavrLAL0cYE/2U6VWqIwEXtk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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