SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b1134d10d3bafd965e1eecd83113ec5da09a4b6ff8897c36272f692be2edefe' 
  AND token = 'h2J8VFZxVrpI37+kCd9mGHb5ZWrJe+Tn3K2gLOlmvsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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