SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38b15e5eca69381e96f0d1cea089dfac5c90f62b074f25bc3042321f3df9816e' 
  AND token = '2wA7hjOg6/1TYMVU9QPefFKgW9GI+0vNByO+sH+e3+I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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