SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8061076336968bdc06b740f12260e4fdbffd4969f76779255c38ad237a5f1360' 
  AND token = 'nOub2+9Hlqz2lAksdZAtwjvRs+XMe2pKHB1V9yp0jPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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