SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49fea9abd8f60748b53c39e6fdca64f248c3d6a7df0330adb3c5b22a406c645f' 
  AND token = 'V++kwwvIjwUWKddI3lvWPT1rF0vpDUkXX4tbN9xCxis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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