SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5827a98004d29e3719fd3c82554e65d3474bfa04c942e39693122e7c69c595cc' 
  AND token = 'IZ5PYVXX86J+NIxwbG+AoWPPaPGc7oZy1G/UQOmXrpg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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