SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '744a1980c9fcbf2f7f035afd97698faeb4c6b1384dff8ad1e214dcc2f5696629' 
  AND token = 'TwYkoLUBZrIZzwtgrevNOXXo6gRKhwrvSAHNSGrBAFg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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