SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f664e0e8525d619c8637674e0848da23f3f2572ae72863d605c92c9cc005ee35' 
  AND token = 'S6D3f45W+VpcEnT7W8JZHDCYq5K+x4ftFCKKvM+YtCA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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