SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '638160e4bf91293772161fd12b7f5a5e2f01504731c423347f9843f887317bad' 
  AND token = 'kxR4GyI4OQy/rbG/Cbxo7sTnV3pBCfWX+/l4Qcdh8dQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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