SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'a85129d2f88aa34fb06eac4caf8c04d17516e3243055dbd886a6c9a12c1cb51e' 
  AND token = 'r9DggHSYejr+2Id2c2P/ITADwxWkW7sAPr0NEPyJ3rQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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