SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '02b7639439badd31772e8224a0086ef5885901aaa2325ec06dba92042bc82a05' 
  AND token = 'i/48TS5nhAkzlFxjapsKc1RgNQG+u5fn9mhY0ANXMDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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