SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b22b10632332bb6b5ef7ffa34cee2fb1ccf57912100622249949cc171398d6b6' 
  AND token = 'jy/RCIxJyk6QPMZ7Ftl68qvKlcYi3b+yFae+nPwzCSE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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