SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '816647834c178318b46af72e029dace03a4df602526c0880d94274e03a269887' 
  AND token = 'sD+0sAjCzHkQ/YrFVN0BbZpS/w29KmVsDbJwiYljX9c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

JSON explain

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