SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b020af7ea29a49295eed136c1e029fbcee93f032632e424602f22138b144331e' 
  AND token = 'w0fmc62zc+ffQQPr94Jp2x3Qc1e/w+Ba3BDfJyiR4Og=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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