SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '69327f15b1ce9974b2373d58b6e5d18a3893e64da064cb5957cfe7104fad243c' 
  AND token = 'F03QESkzkcjVcOupLDbGTFFOo+0AvWKZcyICTVfwYHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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