SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4cf32ed22bbfe4958666df9d17f9f4bacb1d01303dc41e8abf74e63efb8100a7' 
  AND token = 'sCZeHk/3jgypDGoreaVG6FMAAATFI4IeGXiVItNbiVs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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