SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '166177448c75572ee0f709f44a9c8f018a66e719ae9cb0c6869f3aca87e2aa64' 
  AND token = 'U97XusxwA6FowDxStayJLDv+AkTG+6s0Kfgg0I3JyCs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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